Fluid distribution for fluid-solids contacting chambers

ABSTRACT

METHOD AND APPARATUS FOR CONTACTING TWO FLUIDS IN A FLUID-SOLIDS CONTACTING ZONE, SUCH AS AN ADSORPTION ZONE OR A REACTION ZONE. A FIRST FLUID IS DISCHARGED DOWNWARDLY FROM A PASSAGEWAY SPACED ABOVE A BED OF PARTICULATED SOLIDS. FROM A NOZZLE SPACED BELOW THE PASSAGEWAY, A SECOND FLUID IS DISCHARGED UPWARD INTO THE FIRST FLUID DISCHARGED IN A MANNER SUFFICIENT TO PRODUCE A SPRAY OF MIXED FIRST AND SECOND FLUID WHICH PASSES INTO THE BED BELOW. SPECIFIC APPLICATION IS IN HYDROGENATION, HYDROTREATING, HYDROCRACKING, AND HYDRODEALKYLATION REACTION ZONES, WHEREIN A HYDROGEN STREAM IS UTILIZED FOR THE THERMAL QUENCH OF REACTANT HYDROCARBON BETWEEN CATALYST BEDS.

March 28, 1972 BQJYD FLUID DISTRIBUTION FOR FLUID-SOLIDS CONTACTINGCHAMBERS Original Filed Dec. 20, 1968 Figure Figure 2 FIRST FLUID IN r////////m w V mx'rune OUT MIXTURE OUT SECOND FLUID IN Figure 3 N v'r: NTOR David M. Boyd /&4711

A TT'OR/VEYS United States Patent US. Cl. 208-146 8 Claims ABSTRACT OFTHE DISCLOSURE Method and apparatus for contacting t-wo fluids in afluid-solids contacting zone, such as an adsorption zone or a reactionzone. A first fluid is discharged downwardly from a passageway spacedabove a bed of particulated solids. From a nozzle spaced below thepassageway, a second fluid is discharged upward into the first fluiddischarged in a manner suflicient to produce a spray of mixed first andsecond fluid which passes into the bed below. Specific application is inhydrogenation, hydrotreating, hydrocracking, and hydrodealkylationreaction zones, wherein a hydrogen stream is utilized for the thermalquench of reactant hydrocarbon between catalyst beds.

CROSS-REFERENCE TO RELATED APPLICATION This is a divisional applicationof copending application Ser. No. 785,667 filed on Dec. 20, 1968, nowPat. No. 3,556,737, said original application now being restricted tothe apparatus aspects of the present invention and this divisionalapplication being directed to the method aspects thereof.

BACKGROUND OF THE INVENTION The present invention relates to a methodand apparatus for contacting two fluids in a fluid-solids contactingzone such as an adsorption zone or a reaction zone. More particularly,the invention is directed to the contacting of two fluids comprising aliquid phase and a vapor phase in a fluid-solids contacting zone, and tomeans and methods for effecting improved heat exchange between the vaporand liquid phases in the contacting vessel. More specifically, theinvention relates to a new and improved method and apparatus foruniformly distributing mixed phases of vapor and liquid to a granular orparticulated solids contacting zone, as in an adsorption tower or in acatalytic reactor such as a hydrogenation, hydrotreating, hydrocracking,or a hydrodealkylation reactor.

Among the most important of the various commercial processes are thoseinvolving the physical or chemical treatment of hydrocarbons and otherorganic materials with bodies of granular or particulated solid contactmaterials. Many of these processes involve the contacting of two fluidswith the contacting material, and often the two fluids will comprise aliquid phase and a gas or vapor phase. It has been the experience in theart that the introduction of such mixtures of liquid and vapor into abed of particulated contact solids in a uniformly distributed manner, isdiflicult to achieve.

Typical of the art wherein uniform distribution of liquid and gas phasesis necessary but infrequently achieved, is that of catalytichydrotreating and catalytic hydrocracking of various hydrocarbon oils.It is well known that the feed to such a reaction zone comprises liquidhydrocarbon, vaporized hydrocarbon, and a hydrogen rich gas, and thatthis feed is introduced into the reaction zone at an elevatedtemperature. It is further known that the reaction which are encounteredin this catalytic environment are exothermic, and that the temperatureof the vapor phase and of the liquid hydrocarbon phase is increased dueto the exothermic heat of reaction. In order to avoid excessivetemperature within the catalyst bed it is, therefore, typical to arrangethe catalyst in a plurality of separate fixed beds so that diluent orquench vapors may be distributed between the beds during the reaction.The cool quench vapors, normally comprising hydrogen-rich gas, reducethe temperature of the effluent from the bed above, before theliquid-vapor mixture of hydrocarbon and hydrogen is fed into the bed ofcatalyst below.

It is typical in the art to support each individual bed of catalyst upona perforated support plate. It is also typical in the art to introducethe quench hydrogen between the fixed beds of catalyst by means of aperforated pipe grid or other means which is positioned throughout thecross-section of the reactor vessel at the quench point. The effluentfrom the catalyst bed above, thus rains down from the perforated supportplate throughout the crosssectional area of the reactor while the quenchhydrogen is distributed by the perforated grid throughout thecrosssectional area of the reactor.

This prior are type of fluid distributing apparatus comprising aperforated catalyst support plate and a hydrogen quench grid distributoris utilized with the intent of achieving a complete distribution ofliquid and gas phases as uniformly as possible throughout thecross-sectional area of the reactor vessel and of the catalyst bedbelow. It is also the purpose of this known fluid distributing apparatusto provide an intimate contact between hot effluent from the bed aboveand cool quench in order to achieve a uniform temperature of theconstituents that pass into the bed below.

However, this typical prior art design has proven to be relativelyineffective in accomplishing these objectives. The problem iscomplicated by the fact that it is normal to add a relatively smallamount of cool quench hydrogen to a large quantity of hot eflluenthydrocarbon and hydrogen which is leaving the bed above at an elevatedtemperature. The problem is additionally complicated by the fact thatthe amount of cold quench material is relatively small in relation tothe large cross-sectional area which must be covered in order tomaintain a proper uniform distribution of liquid and vapor to the bed ofcatalyst below.

The problem is further complicated by the fact that there is amixed-phase condition within the reactor itself. There is evidence thatthe heavier viscous liquids tend to channel down the side of the reactorwhereas the less viscous liquids tend to channel in the central regionof the catalyst bed with the vaporized hydrocarbon and hydrogen. Theresult is that the temperature encountered within the catalyst bed willbe quite uneven and localized undesirable hot spots are often found ineach bed. It is well known by those skilled in the art that theexistence of the hot spots within the catalyst bed leads toindiscriminant or non-selective hydrocracking of the hydrocarbonconstituents, which is an undesirable result.

Since the more viscous liquid tends to rain down through the supportplate near the walls of the reactor, these viscous materials will alsocontinue to channel along the walls in the beds below. This results inan ineffective quench between the beds, and the resulting continuationof liquid channeling produces further danger of localized hot spots inthe lower catalyst beds.

3 SUMMARY OF THE INVENTION It is, therefore, an object of the presentinvention to provide an improved method and apparatus for contacting twofluids in a fluid-solids contracting zone such as an adsorption zone or.a reaction zone. It is another object of this invention to provide animproved method and apparatus for contacting and distributing mixedphases of vapor and liquid in such contacting zones. It is a furtherobject of this invention to provide a fluid distribution means wherebygreatly improved mixture of vapor and liquid phases occurs at theirpoint of intro duction into a solid contacting zone. It is a stillfurther object of this invention to provide a means of improved heatexchange between a liquid phase and a vapor phase passing to afluid-solids contacting zone where the vapor and liquid are at differenttemperatures, so that the liquid and vapor mixture enters the subsequentcontacting zone at a substantially uniform temperature.

These and other objectives, and the advantages of the present inventionwill become more readily apparent as the invention is more fully setforth hereinafter.

In the present invention, these objectives are achieved by use of anovel catalyst support and eflluent redistribution apparatus whereinthere is incorporated a novel means for injecting the quench hydrogeninto the effluent which passes from the catalyst bed above into thecatalyst bed below.

One embodiment of the invention is clearly set forth in FIG. 1 wherethere is illustrated a artially cut-away elevational view of a typicalhydrocracking reactor vessel containing a plurality of catalyst bedssupported upon the inventive catalyst support and fluid redistributionapparatus. There is also provided FIG. 2 wherein there is illustrated invertical section, the flow pattern which is achieved by the inventivemethod for providing improved thermal quench of the efliuent as itpasses through the catalyst support and fluid redistribution apparatus.Additionally, there is provided FIG. 3 wherein there is illustrated invertical section, various modifications to the basic apparatus whichcomprises one embodiment of the present invention.

The combination fluid distributing deck and catalyst support apparatusof the present invention comprises an imperforate support plate incontradistinction to the typical prior art catalyst support device whichemploys a perforated plate. 'However, the imperforate plate is providedwith a plurality of fluid openings or ports through which the liquid andvapor efiluent from the catalyst bed may be passed via a downcomer intoan open space confined below the support plate and above the catalystbed below. With each fluid opening and downcomer, there is associated ahydrogen quench nozzle which projects upwardly and terminates directlybelow the downcomer and the fluid port of the support plate.

As the fluid eflluent, comprising liquid and vapor phases, is dischargedfrom the downcomer and fluid port, the hydrogen quench is discharged upinto the discharge stream and countercurrent thereto. As a result ofpressure effects, the hot efliuent discharged from the plate above, uponbeing met by the force of upflowing cool hydrogen, is forced outwardlyin a lateral direction and is directly mixed with the quench hydrogen ina manner suflicient to result in a conical spray which then falls ontothe surface of the catalyst bed below in a substantially uniformlydistributed pattern and at a substantially uniform temperature.

In a broad embodiment, therefore, the present invention may becharacterized as a method for contacting two fluids in a fluid-solidscontacting zone which comprises, passing the first fluid downwardlythrough a first fluid passageway positioned above a bed of particulatedsolids and spaced apart therefrom; passing second fluid upwardly througha second fluid passageway positioned a finite distance below the firstfluid passageway and a finite distance above the bed; discharging firstfluid down- 4 wardly into the space confined between the first fluidpassageway and the bed; discharging the second fluid upwardly intodirect contact with the first fluid discharge, whereby a spray mixtureof first and second fluid is produced; and passing the mixture of firstand second fluid from the space into the bed below.

Additionally, the present invention may be characterized as a fluiddistributing means which comprises in combination, an imperforate platecontaining a plurality of openings to a distance from the plate; fluidinlet means below the plate projecting upward and terminating a finitedistance directly under each of the downcomer means; and means forsupplying fluid to each of the fluid inlet means.

In addition, the invention may be further characterized as afluid-solids contacting chamber containing a plurality of fixed beds ofparticulated solids which comprises, a vertically elongated confinedchamber having at least one upper fluid port and one lower fluid port toprovide for a generally vertical flow of fluid therethrough; a pluralityof spaced horizontally positioned imperforate support plate membersholding and retaining particulated contact solids in a plurality ofseparate superimposed packed beds; a plurality of fluid openings spacedover the horizontal area of each support plate member; a fluid downcomermeans extending from each of the openings to a distance from the plate;fluid inlet means below the plate projecting upward and terminating atfinite distance below each of the downcomer means; and means forsupplying fluid to each of the fluid inlet means.

Finally, it may be noted that a preferred embodiment of this inventionmay be characterized as the first of the three embodiments notedhereinabove wherein the first fluid discharged downwardly comprises aliquid phase and the second fluid discharged upwardly comprises a vaporphase.

A clear understanding of the present invention may now be obtained byreferring to the accompanying figures.

DESCRIPTION OF FIGURE 1 As noted hereinabove, one application whereinthe present invention finds specific utility is in the art ofhydrocracking hydrocarbon constituents in a catalytic reaction zone.

FIG. 1 indicates a partially cut-away elevational view of a typicalhydrocracking reactor vessel wherein there is contained four stationaryor fixed beds of hydrocracking catalyst, beds A through D. The reactorvessel comprises a vertically elongated contacting chamber 1, with afluid inlet port 2 located on the top of the vessel and a fluid outletport 3 located on the bottom of the vessel. Additionally, the reactorvessel contains hydrogen quench inlet ports 4 below each of the firstthree catalyst beds, beds A through C.

Each catalyst bed comprises a bed of randomly packed granulated orparticulated catalyst solids 5. The hydrocracking catalyst comprisingeach bed of particulated particles 5 can be any type of catalyst knownin the art, and will typically comprise a catalyst in pilled, spherical,or extruded form. Each catalyst bed is supported upon a layer ofunreactive or inert particulated support material 6. This supportmaterial may be any of the well known prior art inert support materialssuch as ceramic balls, Raschig rings, or Berl saddles. The top of eachbed of catalyst contains an additional layer 7 of the same type of inertsupport material. As is well known to those skilled in the art, it isnormal to provide such a layer of inert material 7 in order to affordimproved distribution for the reactants raining down from the bed abovebefore these reactants reach the active catalyst particles 5. Inaddition, the inert support material 7 provides a layer of high densitymaterial suflicient to keep the bed of lower density catalyst particles5 securely in place under conditions of pressure surge which wouldotherwise dislocate the catalyst particles.

Each bed of catalyst comprising catalyst particles 5, inert supportmaterial 6, and covering layer of inert material 7, is retained andsupported upon the fluid distribution deck of the present invention. Theinventive distribution deck comprises an imperforate support plate 8 inwhich there is contained a plurality of fluid openings 9. These fluidopenings are spaced over the facial area of plate 8 in a substantiallyuniform distribution. Associated with each fluid opening or port 9 thereis provided a fluid downcomer 10 of preferably cylindrical shape whichrises above the support plate to a finite distance. By means of theelevated downcomers 10, it is virtually guaranteed that the liquidfraction of the eflluent which channels or otherwise flows down from thecatalyst bed above will be redistributed and at least to some extentintermixed by being accumulated in a reservoir of liquid upon theimperforate support plate 8 before the liquid can overflow and passdownwardly through the downcomer 10. Associated with each downcomer 10there is provided a perforated means 11. Perforated means 11 may be awoven screen, a slotted plate, a perforated cap device, or any othermeans for allowing flow of fluid therethrough, while obstructing passageof particulated solid material.

As may be seen in FIG. 1, each fluid distribution deck comprising theelements noted hereinabove is located a distance above and away from thecatalyst bed below. This provides that there is a confined open space 13between each catalyst bed. Into this open space there is projected fromquench nozzle 4 a quench header 12 which can be any type of pipe orother conduit device. Directly under each fluid opening 9 there islocated a quench nozzle 14 which projects upwardly from header 12 in asubstantially axial vertical alignment with the associated fluid port 9and downcomer 10. Each quench nozzle 14 terminates a short distancebelow imperforate support plate 8 and the associated fluid opening 9.

In operation, the hydrocarbon and hydrogen feed is passed to thehydrocracking reactor vessel 1 via inlet port 2. The feed mixturecomprising hydrocarbon liquid, bydrocarbon vapor, and hydrogen gaspasses downflow through catalyst bed A. The liquid constituents of thereacted eflluent leaving bed A collect in a reservoir of liquid which ismaintained on imperforate support plate 8. The liquid overflowsdowncomer 10, and passes downwardly with vaporized hydrocarbon andhydrogen gas at an elevated temperature. This elevated temperaturecomprises the feed temperature of the material as it entered the reactorvessel via inlet port 2, plus the temperature rise caused by theexothermic heat of reaction which was absorbed in the reactants as thehydrocarbon was hydrocracked in catalyst bed A. As the eflluentcomprising liquid and vapor phases passes downflow through downcomer 10and is discharged from fluid opening 9, cold hydrogen quench gas isjetted upward from quench nozzle 14 against the effluent dischargestream.

The downflowing fluid from bed A meets the upflowing quench hydrogen toproduce a region of turbulence in which the hot effluent is totallyintermixed with the cold quench hydrogen to produce a relativelyhomogenous mixture of hydrocarbon and hydrogen at a lower temperature.The mixture of efiluent from bed A and quench hydrogen forms a finespray of liquid hydrocarbon which then rains down upon catalyst bed Bbelow in a substantially uniform pattern. The sprayed liquid thus passesinto bed B without channelling, and in a relatively homogenousdistribution with the vaporized hydrocarbon and hydrogen passing intobed B.

The reactants are further hydrocracked in catalyst bed B and theeflluent comprising liquid and vapor phases which leaves bed B has anelevated temperature due to the exothermic heat of reaction which occursdue to the catalytic reaction with bed B. The efl luent then passesthrough the inventive fluid distribution deck which supports bed B andis contacted with upflowing hydrogen quench in the manner which wasdescribed for catalyst bed A hereinabove. This sequence of catalyticreacting and quenching with cold hydrogen is repeated again on thebottom of catalyst bed C. The final reaction mixture of hydrocrackedhydrocarbon constituents and unreacted hydrogen finally leaves catalystbed D and the reactor vessel 1 via outlet port 3, and passes toseparation processing for product recovery by techniques which are wellknown to those skilled in the art.

The effectiveness and the principle of operation for the inventive fluiddistributing deck may now be more clearly understood by referring to theaccompanying FIG. 2.

DESCRIPTION OF FIG 2. l

FIG. 2 is a .vertical section showing one portion of the inventive fluiddistributing deck. FIG. 2 illustrates one fluid downcomer of cylindricalshape and one associated fluid quench nozzle in order that a clearunderstanding of the operating principles of the deck may be set forth.

In FIG. 2, there is shown the imperforate support plate 8 and fluidopening or port 9. Associated with this fluid opening is a downcomer 10which rises above support plate 8 to a finite distance. On the top ofdowncomer 10 there is provided a perforated means 11 which may be awoven screen as noted previously hereinabove. Directly under fluid port9, there is located a fluid quench nozzle 14. It will be seen from FIG.2 that quench nozzle 14 is in substantially axial vertical alignmentwith downcomer 10 and fluid opening 9. In addition, it will be seen thatquench nozzle 14 is located a finite distance below imperforate supportplate 8 and below fluid opening 9.

In operation of the inventive distributing deck, a first fluid passesdownflow via downcomer 10 and is discharged via opening or port 9 whilea second fluid passes upward via quench nozzle 14 and is dischargeddirectly into the discharging flrst fluid. The resulting impingement ofsecond fluid against the flow of the discharging first fluid produces aregion of turbulence whereby first and second fluid thoroughly intermixand the resulting mixture is forced outward laterally, typically in aconical spray configuration.

In the particular embodiment which has been set forth hereinabove indiscussing FIG. 1, the first fluid comprises liquid hydrocarbon,.vaporized hydrocarbon and hydrogen gas. The liquid hydrocarbonconstituents of the first fluid accumulate upon imperforate supportplate 8 and overflow through the perforated screen device 11 to passdownflow through downcomer 10. In addition, the vapor comprisinghydrocarbon constituents and hydrogen flows through perforated means 11with the overflowing liquid constituents of the first fluid. As themixture of liquid and vapor passes downwardly through downcomer 10, itis well known by those skilled in the art that the liquid phase willtend to hug the downcomer walls while the vapor phase will flowdownwardly through the central region of the downcomer. The result isthat there is experienced within downcomer 10, a substantially annularflow of liquid along the surfaces of the downcomer 10.

As the first fluid is discharged downwardly from downcomer 10 via fluidopening 9, it is well known by those skilled in the art that by theCoanda effect, the first fluid will tend to spread out in a spray-likepattern due to the sudden drop in pressure. In order to enhance thespray eflect, support plate 8 has edges around fluid opening 9 which arerounded in the manner shown. However, the degree of spread of the sprayof fluid is limited by the vacuum which is created in the center of thespray pattern, such as in the center of fluid opening 9, as the fluidspreads out. By discharging the second fluid comprising quench hydrogenupward into the center of the discharging first fluid comprising liquidhydrocarbons and vaporized hydrocarbon and hydrogen, the second fluidcomprising quench hydrogen not only overcomes the slight vacuumcontained in the center of the first fluid discharge, but it alsoproduces a pressure increase. The result is that the first fluiddischarging from opening or port 9 is thoroughly intermixed with thedischarging hydrogen quench, and the mixture is thrown out laterallywith a greater force and to a greater distance than would otherwise beexperienced if the second fluid were not impinged into the first fluiddischarge in this manner.

The result is that in the typical hydrocracking reactor vessel, theeflluent leaving each catalyst bed is thoroughly intermixed with coolquench hydrogen resulting in a proper degree of temperature decreasebefore the total mixture passes into the catalyst bed below. Inaddition, it will be seen that the liquid constituents of the efliuentchannelling down from the bed above become thoroughly intermixed anduniformly discharged before passing into the catalyst bed below, so thatany localized channelling which occurs in the catalyst bed above, is notrepeated in the beds below. It will also be seen that since the materialdischarged from fluid port 9 is passed downwardly in a spray pattern,the entire cross-sectional area of the catalyst bed below may be coveredby locating the plurality of fluid openings 9 and the associated quenchnozzles 14 in a substantially uniform pattern over the face area ofimperforate support plate 8.

Other embodiments of the present invention may now be ascertained byreferring to the accompanying FIG. 3.

DESCRIPTION OF FIG. 3

FIG. 3 illustrates in vertical section a portion of the fluiddistribution deck wherein there is again shown the imperforate supportplate 8 and fluid opening or port 9. A cylindrical downcomer extendsfrom fluid opening 9 and rises to a finite distance above deck 8. On thetop of the downcomer 10 there is provided the perforate means 11 forpassing fluid into downcomer 10 while retaining particulated solids inthe bed above. Directly under fluid opening 9 and in substantiallyvertical axial alignment with downcomer 10 and fluid opening 9, there isprovided a quench nozzle 14.

In addition, in this embodiment of the inventive apparatus there is alsoprovided a helical insert 15 within downcomer 10. This insert provides ahelical path for the downflowing first fluid so that, in particular, theliquid constituents of the first fluid are imparted with a centrifugalforce when they are discharged from fluid opening 9. The centrifugalforce will assist in discharging the first fluid outwardly to a greaterlateral distance than might otherwise be experienced. While helicalinsert 15- is shown to be a single helix in the illustrated embodiment,insert 15 would preferably be a multiple helical device since otherwisethe material being discharged from fluid opening 9 via the helix wouldbe jetted outwardly in a single path in a single direction. By providinga triple helix, for example, the fluid would be discharged from fluidopening 9 in three paths spaced at 120 apart. Where a quadruple helix isemployed, the first fluid would be discharged from fluid opening 9 infour centrifugal paths spaced 90 apart.

It will also be seen in FIG. 3 that there can be provided a flared skirt16. This flared skirt enhances the Coanda effect noted hereinabove sothat the fluid is given a greater flow path in order to enhance thespreading out effect which is experienced as the fluid leaves thedischarge port or opening 9.

PREFERRED EMBODIMENTS The method of operation of the inventive fluiddistributing means is readily ascertainable to those skilled in the artfrom the teachings that have been presented hereinabove, and theadvantages to be accrued from the inventive device and method areequally apparent.

It must be realized, however, that the effectiveness of the device andmethod will depend upon the specific environment in which it isutilized, and in the specific dimensional design of the deck as it isspecifically employecl.

The dimensions for the inventive distributor deck and its elementscannot be set forth herein with great specificity since a great manyfactors will affect the dimensions which are required in any specificenvironment. Among the factors to consider in a hydrocracking reactor,for example, are the rate of flow of the efiluent from the catalyst bedabove to the bed below, and the rate of flow of the quench hydrogen. Thevapor-liquid distribution of the effluent flowing from the bed abovewill also effect the dimensions which are required in the design of theinventive distributor deck, and the temperature and pressure of theeffluent will have a pronounced effect upon this vapor-liquiddistribution. In addition, it must be realized that the temperature atwhich the quench hydrogen is introduced via nozzle 14 will also have apronounced effect on the degree of quench which is ex perienced and onthe spray effect which is produced. Finally, molecular weights must beconsidered, and the density of the various liquid and vapor phases is ofprimary consideration.

While the inventive method of contacting downflowing first fluid withupflowing second fluid to produce a spray of first and second fluidpassing into the bed below can be eflectively achieved in the inventiveapparatus by passing the first fluid downwardly through the fluid portor opening 9 without the use of the downcomer 10, this is not apreferred embodiment since the use of the downcomer 10 provides a liquidreservoir on Support plate 8, whereby liquid channelling down from abovecan be remixed before passing to the next bed below. Accordingly, it maybe set forth that a preferred apparatus will include the illustrateddowncomer 10. The typical downcomer 10 will extend at least two inchesabove the imperforate support plate 8 and fluid opening 9, and in manyembodiments the downcomer height will be more than two inches. Normally,downcomer 10 will have a circular cross-section with a preferreddiameter of about four inches, but in specific applications downcomer 10and fluid opening 9 may have diameters from /2 inch to 8 inches or morein range. The distance of nozzle 14 from fluid opening 9 and downcomer10 will depend to some extent upon the diameter of fluid opening ordischarge port -9 as well as the other considerations noted in theparagraph above, such as temperature and flow rate. Thus, the distanceof nozzle 14 from fluid opening or port 9 could be varied in the rangeof from a fraction of an inch to twelve inches.

It will be apparent to those skilled in the art that the number of fluidopenings or ports 9 which are provided in imperforate support plate 8will vary with the specific application. However, there should be asuflicient number of fluid openings substantially uniformly distributedon support plate 8 so that the cross-sectional area of the top of thecatalyst bed below is thoroughly contacted with the spray of effluenthydrocarbon and quench hydrogen in a substantially uniform manner. Thus,the number of fluid openings 9 in support plate 8 could range from fourto one hundred or even more. Primarily, the pressure drop across thefluid distribution deck of the present invention must be considered inestablishing the number of fluid openings. Since it is normal to seek alow pressure drop, at least six openings per deck should be provided inany typical hydrocracking operation.

It will also be apparent to those skilled in the art that the spacing ofthe fluid openings 9 and associated downcomers 10 over the facial areaof imperforate support plate 8 will vary with the specific applicationand with the number of fluid o enings incorporated in the inventivefluid distribution deck. Thus, in a very small fluidsolids contactingchamber wherein only a single downcomer and associated quench nozzle isnecessary, the fluid opening will be positioned in the center of thecircular plate. Where four openings are required, they will be typicallybe spaced equidistant away from the center of radii at from each other,in order to fully distribute the spray in a substantially uniform mannerover the circular cross-section of the particulated solids bed below.Where seven openings are required, they may be positioned with oneopening in the center of the circular support plate, and hte other sixopenings spaced away equidistant from the center on radii at 60 fromeach other. Where a great many fluid openings are required in a largechamber, for example ten or more, the fluid openings may be spaced overthe face of the irnperforate support plate in concentric circles, in asquare pitch distribution, in a triangular pitch distribution, or in anyother pattern sufiicient to provide a substantially uniform pattern ofspray over the cross-section of the bed below.

It will be noted that in the application above, the specific examplecomprises an illustration wherein a hydrocarbon was catalyticallyhydrocracked. It is well known to those skilled in the art that thecatalyst will deteriorate as the operation proceeds so that catalystactivity and selectivity gradually becomes lower during the life of thecatalyst. This then requires that the inlet temperature of the tfluidentering via inlet port 2 be gradually increased over the life of thecatalyst. This increase of temperature will cause a change in thevapor-liquid equilibrium of the effluent which is discharged from anygiven catalyst bed, thus causing a change in the hydraulics of the fluiddistributing deck. In order to compensate for this change so that thespray pattern of the inventive fluid distribution apparatus is not lost,those skilled in the art will perceive that the temperature of thequench hydrogen can be changed or that the rate of the quench hydrogencan be changed sufliciently so that the hydraulic balance necessary forthe most effective operation of the inventive distributor deck willremain in substantial equilibrium throughout the life of the catalyst.

While the embodiments disclosed hereinabove have been directed to theexothermic catalytic reaction of hydrocarbons in a hydrogen atmosphere,the invention is not so limited. Those skilled in the art will perceivethat the method of contacting two fluids in a fluid-solids contactingzone and the apparatus therefor have equal application in anyfluid-solids contacting zone such as in adsorption zones. Additionally,the apparatus is not limited to the support of fixed beds ofparticulated contact solids, but it can also find application as thefeed distribution apparatus at the top of the first bed contained withinthe contacting chamber. The method and apparatus also is not limited tothe specific fluids discussed hereinabove. Thus, the first fluid passeddownwardly need not be a mixture of liquid and vapor phases, but it alsocould be solely a liquid phase, or solely a vapor phase. And the secondfluid passed upwardly need not be limited to a gas or vapor phase, butit also could be solely a liquid phase, or a mixture of liquid phase andgas phase. Furthermore, the second fluid passingly upwardly need not bea low temperature fluid quenching a higher temperature downflowing firstfluid, but it may be at the same temperature above the first fluid, orit may be at a temperature above the first fluid temperature in order toprovide a heat input into the fluid-solid contacting zone. Additionally,the down comer means need not have a circular cross-section and it couldbe associated with more than one fluid inlet nozzle 14. In such anembodiment, of course, the resulting spray mixture would be a conicalspray.

However, from the disclosure hereinabove, it will be readily apparentthat the particularly preferred embodiment of the present inventioncomprises application of the inventive apparatus and contacting methodwherein the fluid-solids contacting chamber is an exothermic catalyticreaction zone for the processing of hydrocarbon constituents in thepresence of hydrogen. Additionally, as noted hereinabove, specificapplication of the present invention is in hydrogenation, hydrotreating,hydrocracking, and hydrodealkylation reaction zones wherein a hydrogenstream is utilized for the thermal quench of reactant hydrocarbonbetween catalyst beds.

It will be apparent to those skilled in the art that in such preferredapplications, the pressure wherein the inventive apparatus andcontacting method are functional will be in the range of from p.s.i.g.to 3000 p.s.i.g. For example, in the hydrogenation of benzene to producecyclohexane, a pressure range of from 100 p.s.i.g. to 500 p.s.i.g. isnormally utilized. In the hydrotreating of light hydrocarbon fractionssuch as gasoline or naphtha to saturae olefins and to remove sulfur,nitrogen, oxygen, metallic, and other impurities, a pressure in therange of from 100 p.s.i.g. to 1000 p.s.i.g. is typically utilized. Inthe hydrotreating or hydrocracking of hydrocarbon fractions heavier thannaphtha such as kerosenes, gas oils, cycle oils, reduced crudes, etc.,pressures in the range of from 100 p.s.i.g. to 3000 p.s.i.g. may beutilized. In the hydrodealkylation of alkylbenzenes to produce benzene,a pressure in the range of from 300 p.s.i.g. to 1000 p.s.i.g. isnormally employed.

In addition, those skilled in the art will realize that for theseprocesses the inventive apparatus and contacting method will be utilizedat a temperature in the range of from 300 F. to 1500 F. For example, inthe hydrogenation of benzene to produce cyclohexane, a temperature rangeof from 300 to 600 F. is normal. In the hydrotreating of lighthydrocarbons such as gasoline or naphtha fractions, a temperature rangeof from 500 to 900 F. is typically utilized. In the hydrotreating orhydrocracking of hydrocarbon fractions heavier than naphtha, atemperature range of from 500 to 1000 F. may be employed. In thehydrodealkylation of alkylbenzenes to produce benzene, temperatures inthe range of from 1000 to 1500 F. may be utilized.

In these hydrocarbon processes wherein the inventive apparatus andcontacting method find particular utility, the beds of particulated orcontact solids will normally comprise catalyst containing one or moremetallic components selected from Group VIB and Group VIII of thePeriodic Table (Periodic Table, Handbook of Chemistry and Physics, 43dedition). These metallic components are typically supported on arefractory inorganic oxide having a pilled, spherical, or extruded form,although any granular or particulated form may be employed. Typicalsupport materials of this type are alumina, silica, magnesia, zirconia,kieselguhr, diatomaceous earth, etc., either singly or in combination. Atypical hydrogenation catalyst will comprise a Group VIII metal on therefractory inorganic oxide, and a preferred catalyst for hydrogenationof aromatic hydrocarbons comprises nickel on kieselguhr. A typicalhydrotreatin'g catalyst will contain silica and alumina and a Group VIIImetal or a Group VI-B metal or a combination of metals thereof. Onepreferred hydrotreating catalyst comprises silica, alumina, nickel,molybdenum, and cobalt. A typical hydrocracking catalyst will contain atleast one metallic component selected from the metals of Group VI-B andGroup VIII such as platinum, palladium, nickel, or molybdenum and acomposite of silica-alumina. A typical catalyst for thehydrodealkylation of alkyl aromatics will comprise a Group VIB metal,such as chromium, molybdenum, or tungsten, on the refractory inorganicoxide support material, and one particularly preferred catalystcomprises chromium oxide on silica-alumina.

In summary, therefore, a preferred embodiment of the present inventionmay be characterized as a method for contacting two fluids in afluid-solids contacting zone which comprises, passing first fluid at afirst temperature, downwardly through a first fluid passageway spacedabove a bed of particulated solids and spaced apart therefrom; passing asecond fluid at a second temperature upwardly through a second fluidpassageway positioned a finite distance below the first fluid passagewayand a finite distance above the bed; discharging first fluid downwardlyinto a space confined between first fluid passageway and the bed;discharging the second fluid upwardly into direct contact with the firstfluid discharge whereby a mixture of first and second fluid is producedhaving a third temperature intermediate to the first and secondtemperatures; and passing the mixture of first and second fluid from thespace above into the bed below.

Further, a particularly preferred embodiment of the present inventionmay be characterized as a method in the paragraph immediately abovewherein the contacting zone comprises a catalytic reaction zone, thefirst fluid comprises hydrocarbon, the second fluid comprises hy drogen,and the bed of particulated solids comprises one of the group consistingof a hydrogenation catalyst, a hydrotreating catalyst, a hydrocrackingcatalyst, and a hydrodealkylation catalyst.

The invention claimed:

1. A method for treating a hydrocarbon with hydrogen by contacting twofluids through a plurality of stages of spaced fluid-solids contactingzones which comprises:

(a) collecting a first hydrocarbon fluid in a first bed containingparticulated solids and passing said first fluid through a firstrestricted passageway under pressure whereby said first fluid is passedin a stream downwardly at high velocity toward a next below bed;

(b) jetting a second fluid comprising hydrogen through a second fluidpassageway of substantially smaller diameter than said first restrictedpassageway, said second fluid being passed upwardly, axially anddirectly into said downwardly directed high velocity stream to create aregion of turbulence at the area of impact thereof to thoroughlyintermix said first fluid and second fluid and force said fluids outwardlaterally in a conical spray configuration to thereby thoroughlyintermix the same;

(c) passing said thoroughly intermixed first and second fluidsdownwardly into a second bed of particulated solids; and

(d) repeating said steps (a) and (b) with respect to said second bed.

2. Method of claim 1 wherein said second fluid is a quench fluid.

3. Method of claim 1 wherein said first fluid passageway comprises firstconduit means.

4. Method of claim 3 wherein said first fluid is passed through saidfirst conduit means in a downward helical path.

5. Method of claim 1 wherein said first fluid passageway comprises afluid port above said intermixing zone and said second fluid passagewaycomprises conduit means terminating a finite distance below said fluidport.

6. Method of claim 1 wherein said first fluid comprises liquid and saidsecond fluid comprises vapor.

7. Method of claim 1 wherein said contacting zones comprise catalyticreaction zones, said first fluid comprises mixed hydrocarbons, saidsecond fluid comprises hydrogen, and said beds of particulated solidscomprise one of the group consisting of a hydrogenation catalyst, 21hydrotreating catalyst, a hydrocracking catalyst, and ahydrodealkylation catalyst.

8. Method of claim 7 wherein said bed comprises hydrocracking catalyst.

References Cited UNITED STATES PATENTS 2,863,931 12/1958 Summers 23-2883,075,752 1/1963 Leva 261-113 3,186,935 7/1965 Vaell 208-57 3,425,8102/1969 Scott 261-113 2,475,822 7/1949 Cummings 208-146 2,904,502 9/1959Shapleigh 208-146 3,144,404 8/1964 Tyson 208-143 3,152,065 10/1964 Sharpet a1. 208-158 HERBERT LEVINE, Primary Examiner US. Cl. X.R.

